Storage rack installation

ABSTRACT

A storage rack installation having a rank of movable storage racks disposed in lateral juxtaposition and adapted to be shifted individually or in groups by associated drive means to open an access passage between any two selected neighboring racks. Each rack is provided with a reversible motor and is mounted on a plurality of wheels at least one of which is coupled to the associated motor. Control means are provided comprising a common control unit which determines the direction of rotation of the motors of the single or group of racks that is to be shifted, by reference to the position of two-way switch means of which one is associated with each rack, and which switch means adopt an open or closed position depending upon the existing position of the rack with which they are associated.

United States Patent [72] inventor Erwin Ruoss 3,071,260 1/1963 Estep 21 1/1.5X

Tschill, Naters,, Switzerland FOREIGN PATENTS Q15; 33 209,525 12/1966 Sweden 211/162 y 815,901 6/1969 Canada 211/162 [45] Patented Apr. 20, 1971 [73] Assignee Josef Zurschmitten AG. Primary ExaminerNi1e C. Byers, Jr.

Brig, Switzerland Attorney-Wenderoth, Lind & Ponack [32] Priority May 9, 1968 [33] Switzerland 3 7099/63 ABSTRACT: A storage rack installation having a rank of movable storage racks disposed in lateral juxtaposition and adapted to be shifted individually or in groups by associated [54] STORAGERACK INSTALLATION drive means to open an access passage between any two 4Claims3Drawing Figs selected neighboring racks. Each rack 1s provided with a reversible motor and 1s mounted on a plurality of wheels at [52] US. Cl 1 211/ 1.5 least one f which is coupled to the associated meton Comm] [511 f Cl A47f 3/08 means are provided comprising a common control unit which [50] Fleid of Search 21 1/ 1.5, determines h direction of rotation of the motors of the Single 1621 175 or group of racks that is to be shifted, by reference to the position of two-way switch means of which one is associated [56] References Clted with each rack, and which switch means adopt an open or UNITED STATES PATENTS closed position depending upon the existing position of the 2,812,069 1 1/ 1957 Trammell 21 1/162 rack with which they are associated.

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PATENTEU APRZOIHH v 8575298 sum 2 BF 3 INVENTOR 3 ERWIN RUOSS ATTORN EYS FIG.3

INVENTOR ERWIN RUOSS Y Y WQ M ATTORNEYS STORAGE RACK INSTALLATION This invention relates to a storage rack installation comprising a rank of movable storage racks disposed in lateral juxtaposition and adapted to be shifted sideways individually or in groups by associated drive means to open an access passage between any two selected neighboring racks, each rack being provided with a reversible motor.

Storage rack installations have already been proposed in which a reversible motor is provided for shifting the racks individually in the required direction by shafting extending crosswise of the racks. The racks can each be coupled to the shafting by manually operable coupling means. In another known form of construction the shafting is replaced by an endless rope to which the racks can be coupled by suitable coupling means. Finally, rack installations have been proposed in which, as in the present case, a shaft or endless rope is dispensed with and a separate reversible motor provided in each rack for shifting the rack by means of a friction wheel which is directly coupled to the motor or of a pinion which meshes with a toothed rack preferably mounted below floor level.

However, these drive means are suitable only when the shifted weights are light or when there is no risk of for instance the toothed rack being fouled. Moreover, it has been the practice to provide a complete set of control means for the reversal of the direction of the motor in each individual storage rack. A functional fault in the control means of individual racks can therefore result in the motor of say one rack revolving in the wrong direction and this fault not being immediately detected, particularly when a group of storage racks is being shifted.

The proposed storage rack installation eliminates these shortcomings. The invention consists in that each rack is mounted on a number of floor and track wheels of which at least some are geared to the associated motor, and in that control means are provided comprising a common control unit which controls the direction of rotation of the motor or motors of the single or group of racks that is to be shifted, by reference to the position of two-way switch means of which one is associated with each rack and which assume a position depending upon the existing position of the rack with which they are associated.

An embodiment of a storage rack installation according to the invention will be more particularly described with reference to the drawings in which:

H0. 1 is a view of the underside of an individual rack FIG. 2 is a schematic front elevational view of a storage rack installation comprising four individual racks, and

FIG. 3 is a diagrammatic representation of electrical circuitry suitable for operating a rack installation according to the invention.

Referring to HO. 1 each mobile rack l is equipped with an electric motor 2 which applies torque through a pinion 3 directly to floor wheels 4 and track wheels 5. The wheels 4 and 5 that are mounted on the driven axle are connected by lengths of shafting 6 and coupling clamps 7 and thus operatively connected to the motor.

H6. 2 is an illustrative embodiment of a rank of storage racks which comprises four separate racks 10a to Mid so disposed between sidewalls W that the racks can be shifted to and fro by their respective motors to open up an access passage 1i between any two neighboring racks. In the drawing a passage has been opened up between 10b and 10c. Normally the width of the passage will be arranged to be somewhat wider than the width of one rack. However, this width may be chosen to meet specific requirements. Two pushbutton switches B2 and 13 are provided on the front panel of each mobile rack.

Each rack 10a to 10d is further provided with a control member, for instance in the form of a magnetic switch 14, fitted with a bistable changeover contact. The magnetic switches 14 are operable by pairs of permanent magnets N15a-Ni5d and Sl6a-Sl6d, mounted on a fixed guide rail l7 and preferably located either above or behind each rack, the magnets Nl5a-Nl5d operating the contact in the cooperating magnetic switch 14 to start'the motor for shifting a rack that is in its left-hand end position to the right. Conversely the magnets S16a-Sl6d operate the contact in the cooperating magnetic switch for shifting a rack that is in its right-hand end position to the left. Conveniently the magnets Nl5a-Nl5d and Sl6a-Sl6d are located at different levels and relatively spaced across the racks. In a modification of this arrangement which is not shown in the drawing -the said control members, i.e. in the illustrated embodiment the magnetic switches 14, may be fixed in a suitable position outside the racks, in which case the racks are each provided with actuating elements for changing over the operative position of the control member.

Fitted to the two bottom longitudinal edges of each rack unit are bar-shaped pedal switches 9 which interrupt the supply of current to the motor when their contacts are closed and which are thus adapted to stop the associated group of racks.

Moreover, on one longitudinal side of each rack some distance away from the end face of the rack there is a releasing switch 18 which must be depressed for electrically unlocking the control means prior to a contemplated shift of one of the racks. All the switching elements in each rack are connected by cable to a control box 19 associated with the respective rack. The control boxes 19 of neighboring racks are interconnected by multicore cables. Each rank of racks comprising any desired number of racks, in the illustrated embodiment the rank comprises four units 10a to 10d, is also provided with a common main control cabinet 21 which contains all the apparatus needed for the joint control of the racks in the rank, and which is connected by a multicore cable to the nearest rack 10a.

With reference to the general circuit diagram shown in FIG. 3, the panel enclosed by a discontinuous line on the left-hand side of the diagram contains the circuitry of the main control cabinet 21, whereas the adjacent divisions separated by dotdash lines represent the control elements contained in the individual racks 10a to 10d.

The manner in which the control system functions will now be more particularly described with reference to this diagam. it is assumed that the racks are in the positions shown in FIG. 2, Le. the two first racks 10a, 10b on the left are in their lefthand end positions and separated by an open access passage 11 from the two other racks 10c, 10d which are in their righthand end positions. Let it now be assumed that it is desired to move the rack 10b to the right to create a passage between the two racks 10a and 10b.

The operation of a main switch (not shown) connects the primary of a transformer 24, which for safety reasons transforms the mains voltage to a lower voltage through fuses 23 to the two phases R and S of the mains network. A conductor 25 is connected by contacts 33b and 34b to one terminal a of the secondary winding of the transformer 24. Since it is desired to move the rack 10b to the right the appropriate pushbutton switch 13 on this rack for a shift to the right is briefly depressed. Current from the conductor 25 thus passes through the closed contacts of this switch. Since the magnetic switch 14 of the rack faces the magnetNlSb, the switch blade of the magnetic switch is in position for a shift of the rack to the right. The depression of the pushbutton switch operates a relay 44 having contacts a-f.

However, since the relay 44 would release when the pushbutton is released, the relay is self-holding in a circuit beginning at the secondary terminal a of the transformer 24 and closed via the contacts zl and 330, a conductor 26, the closed contact 44b, the relay winding 44, a contact 43f, a contact of the magnetic switch 14 and a conductor 54 which leads back to the other terminal b of the secondary winding of the transformer 24.

All the working contacts of relay 44 are now closed, causing contact 440 to apply voltage through a line 53 to a coil R for operating the contacts R' of a duplex contactor in the main control cabinet 21. Consequently the phases RST are connected by the contacts a, b, c, via supply leads 50, 51, 52 and the closed relay contacts 44d, 44c to the motor 2b which therefore begins to shift this rack b to the right.

Closure of the contact 440 also applies voltage via a conductor 30bc to the next rack 100 in which a relay 46 would operate if this rack were likewise on the left of the passage ll. However, in the case here considered the contact of the magnetic switch 14 in rack 10c is in the position for a shift to the left because this switch aligns with the magnet Sl6c. Consequently the relay 46 cannot operate.

At the same time as the group of contacts R of the duplex contactor in the main control cabinet 21 operates, an auxiliary relay 34 is energized by a contact Rd which is coupled with the group of contacts R, and which holds in operate position through a contact 34a which is now closed and a break contact 310. Operation of relay 34 removes potential from conductor 25 because its contact 34b opens, so that no other rack can be started up via this line.

As soon as the rack 10b has reached the right-hand side of the former passage and a fresh access passage has thus been opened between the two racks 10a and 10b the contact of the magnetic switch 14 in rack 10b changes over to the position for a shift to the left and thus deenergizes the relay 44. The contacts 44a 44f of this relay therefore return to their positions of rest and cause the contacts R of the duplex contactor to release. The shifted rack therefore comes to a stop.

No other rack can be started because the relay 34 still holds and its contact 34b disconnects the conductor 35 which otherwise supplies voltage to the pushbutton switches. Before the racks can be moved again the release key 18 on the rack which is on one side of the passage must first be operated to apply a potential pulse from terminal b of the transformer 24 via a conductor 29 to a relay 31, causing this relay to operate. For safety reasons this relay may operate with delay. A break contact 310 opens the holding circuit of relay 34 which therefore releases. The release of this relay may be delayed as an alternative to the delayed operation of relay 31. When relay 34 has released the contact 34b recloses and reconnects conductor 25 to the control potential. The system is thus ready for a fresh shift of racks. From the control point of view the time relay Z which is likewise contained in the main control cabinet 21 is merely a safety device for the protection of the motors 2a2d. It is energized via contact Le or Re when one of the contact groups D' or R of the duplex contactor closes and remains in operate position until the said group of contacts opens again.

If for any reason whatsoever, such as a faulty insulation in a control circuit or a sticking contact, a motor should continue to run after the relative rack has reached one of its end positions, contact Z1 will interrupt the supply. The delay to which relay Z is preset slightly exceeds the time .1: required by the rack to travel from one end position to the other. Moreover, for the safety of personnel and equipment each rack is fitted with a bar-shaped pedal switch 9 which pennits the motor to be stopped at any time. Operation of the pedal switch causes a relay 33 to be energized via a conductor 28. The relay contacts 33a and 33b open and break the holding and control circuits of the relays 4l--48 which therefore return to their release positions and at once stop the rack.

The events will now be described which occur when the two racks 10b and 10c are both shifted to the left to open an access passage between the two racks 10c and 10d. After the previously described control operation has been completed, the three racks 10b, 10c and 10d are all in close juxtaposition on the right, and an access passage 11 has been opened between the two racks 10a and 10b.

In this position of the racks in the illustrated rank the contacts of the magnetic switches 14 of racks 10b, 10c. and 10d are all held by the associatedmagnets 816b, 516a and SIM in the positions preparatory to a shift to the left.

By briefly depressing the pushbutton switch 12 on rack 10c for effecting a shift to the left the relay 45 is energized and operates, the contacts 45a-e opening and contact 45f closing. Via contact 45a and conductor 20cb the relay 43 in rack 10b is simultaneously operated so that the relay contacts 54a--e likewise close and contact 43f opens. The two relays 45 and 43 hold in operate position via their respective holding contacts 45b and 43b.

At the same time the group of contacts L of the duplex contactor in the main control cabinet 21 is closed via contact 45c, the parallel contact 43c and the conductor 27. Consequently the mains phases in the sequence RTS are. connected by the contactor contacts a, c, b and the conductors 50, 51, 52 via the closed contacts 43d and 43e to the motor 2b of rack 10b and via the closed contacts 45d and 45e to the motor 20 of the rack 100. The two racks 10b and therefore both begin to shift from right to left. At the same time the time delay relay Z is energized and the locking relay 34 operates, disconnecting all the pushbutton controls from voltage.

As soon as the two racks 10b, 100 have reached a position on the left-hand side of the fresh access passage that is to be opened, the contact of the magnetic switch 14 is changed over to right-hand shifting by the cooperating stationary magnet, cutting off the two relays 45 and 43 which release, their contacts returning to position of rest. Consequently the coil L of the contact group L in the duplex contactor is likewise deenergized and these contacts open to stop the further supply of current. The racks stop, a fresh passage having been formed between the two racks 10c and 10d.

For opening an access passage between any two racks the release key 18 in the existing passage must always be pressed. In the position now reached this would be the releasing switch on rack 100. It will be understood from the above explanations that a passage will always open in the desired position by pressing the pushbutton which is associated with the required direction of shift on the rack facing the existing passage.

A particular advantage of the described control system is that only those switching elements that are specifically associated with each rack need be mounted in the rack, whereas the elements that are common to all the racks are located in a main control cabinet 21. Moreover, if an existing rank is to be extended by the provision of more racks, these can simply be added to the last rack in the existing rank which does not have to be modified in any way because the control means in each rack form a completely self-contained unit.

When several racks need shifting for opening a passage in a required position, only one of the pushbuttons 12 or 13 need be depressed, as has already been explained. The other racks which must participate in the required shift are coupled, according to the direction of the required shift, via the respective conductors 29ba, 290b, 29dc, 30ab, 30bc and 30cd.

Shiftable terminal racks such as 10a may have to be fitted with two releasing keys 18 and 18. These two keys are then connected in parallel, as indicated in the circuit diagram. The key numbered 18 must be depressed when a passage has been opened between the left-hand sidewall W and the rack 10a and afresh passage is required in a different position.

I claim:

l. A storage rack installation comprising a rank of movable storage racks disposed in lateral juxtaposition, associated drive means for shifting said racks individually or in groups to open an access passage between any two selected neighboring racks, a reversible motor for each rack, each of said racks being mounted on a plurality of wheels with at least one of said wheels coupled to its associated motor, two-way switch means associated with each rack, control means for said motors comprising a common control unit determining the direction of rotation of the motors of the single or group of racks that is to be shifted upon reference to the position of said switch means and said switch means having an open or closed position depending upon the existing position of the rack with which they are associated.

2. A rack installation according to claim 1 wherein each two-way switch means is associated with two relay sets alternatively operable according to the position of said twoway switch means.

3. An installation according to claim 1 wherein said 

1. A storage rack installation comprising a rank of movable storage racks disposed in lateral juxtaposition, associated drive means for shifting said racks individually or in groups to open an access passage between any two selected neighboring racks, a reversible motor for each rack, each of said racks being mounted on a plurality of wheels with at least one of said wheels coupled to its associated motor, two-way switch means associated with each rack, control means for said motors comprising a common control unit determining the direction of rotation of the motors of the single or group of racks that is to be shifted upon reference to the position of said switch means and said switch means having an open or closed position depending upon the existing position of the rack with which they are associated.
 2. A rack installation according to claim 1 wherein each two-way switch means is associated with two relay sets alternatively operable according to the position of said two-way switch means.
 3. An installation according to claim 1 wherein said common control unit is a duplex contactor comprising two separately controlled groups of contacts.
 4. An installation according to claim 1 wherein a plurality of said wheels are coupled together by shafting. 